It may happen during driving in curves but also in case of unevennesses of the pavement that one wheel of an axle moves farther away from the vehicle body than the other wheel of the same axle. The imaginary connection line (axle line) between the wheel centers is sloped in relation to a plane associated with the vehicle body (chassis plane), whereas the axle line extends in parallel to the chassis plane in the state of rest. The angle formed between the axle line and the chassis plane will hereinafter be associated as a slope angle with this slope.
The difference between the distances between the two wheels, on the one hand, and the motor vehicle body, on the other hand, may lead to an undesired rolling of the motor vehicle body, as a result of which the safety of travel is greatly compromised, especially at high speeds. To reduce this rolling, a stabilizer, which is mounted on the vehicle body and is provided with a torsion bar, is fastened with its ends to the wheel carriers or transversal swinging arms associated with the wheels of the axle. An increasing slope angle will then lead to an increasing torsion of the torsion bar, as a result of which it is achieved that the spring force of the stabilizer will counteract the slope of the chassis plane in relation to the axle line. The risk for an excessive roll is thus reduced.
Stabilizers provided with torsion bars consequently have the task of reducing the tendency of the motor vehicle body to roll during travel in a curve and are known in the state of the art.
Even though the above-described function of the stabilizer is highly desirable in on-road vehicles, a different behavior of a motor vehicle is required in the case of off-road vehicles, because great unevennesses in the terrain leads to the desire to have a great slope angle in order to enable all wheels to have a good road grip. The more slippery the ground, the more important does this become, because a sufficient force can be transmitted to the ground from the wheel only in case of good road grip. An oblique position of the motor vehicle body shall also be kept as small as possible in the case of a great difference between the distances of the two wheels of one axle in order to make it difficult for the vehicle to tip over when the vehicle is being moved at right angles to a slope. Furthermore, the stabilizer may be overloaded and consequently damaged due to the unevennesses or slopes in the terrain, which cause the great slope angle. The effect of a stabilizer is therefore rather undesired in off-road vehicles.
The above-mentioned different requirements on stabilization for road travel, on the one hand, and for off-road travel, on the other hand, do not represent any difficulties for off-road vehicles, which are not used for road travel, and for on-road vehicles, which are not used on terrain, because the motor vehicles can be individually adapted for their respective fields of use.
However, off-road vehicles have become popular for some time and also attractive to many people as on-road vehicles, so that the requirement for a relatively slight stabilization on terrain is contrasted by the requirement for a relatively strong stabilization during road travel.